Apparatus for fastening articles

ABSTRACT

A fastening tool for driving adhesive through a solid workpiece into the interface thereof with a base member includes a chamber for liquid adhesive having a smaller chamber or bore terminating in an exit nozzle. A plunger movable in the bore is impacted by a piston driven member to propel adhesive from the exit nozzle at high speed to drive the adhesive through the workpiece. The chamber is heated to permit use of hot melt adhesives.

0 United States Patent 11 1 1111 3,887,l 13 Obergfell 1 June 3, 1975 [5 APPARATUS FOR FASTENING ARTICLES 2,705,953 4/1955 Potez 128/173 H 75 Inventor: Allen R. Obergfell, Park Ridge, 111. $5 IIIIIII u 7 A D C F 3,221,948 12/1965 Kalist 3] ss'gnee 13:3 orporauon ranklm 3,291,350 12 1966 Malec 222/383 x 3,370,770 2/1968 Henning et a1. it 227/9 [22] Filed: July 19, 1973 [2]] pl No: 3 0 20 Primary Examiner-Stanley H. Tollberg 0 Assistant Examiner-Charles A. Marmor Related p lon Data Attorney, Agent, or Firm-Mason, Kolehmainen,

[60] Continuation of Ser. No. 172,980, Aug. 19, I972, Rathburn & Wyss abandoned, which is a division of Ser. No. 776,712,

Nov. 18, 1968, Pat. No. 3,616,034. ABSTRACT [52] US. Cl. 222/146 HE; 222/334; 222/333 A fastening tool for driving adhesive through a solid 51 Int. Cl. G01r'11 00 workpiece into the interface thereof with a base 53 Field f Search ZZZ/M6 HE 14 H, 3 ber includes a chamber for liquid adhesive having 21 222 377 255 371 3 0 3 3 335 7 smaller chamber or bore terminating in an exit nozzle. 227/9; 123 173 H A plunger movable in the bore is impacted by a piston driven member to propel adhesive from the exit nozzle 5 R fe n Cited at high speed to drive the adhesive through the work- UNITED STATES PATENTS piece. The chamber is heated to permit use of hot 1 2,039,881 5/1936 Carter 222/334 x m t adhes'ves 2,259,857 10/1941 Ostendorf 222/334 X 2 Claims, 7 Drawing Figures In, s4

i as as APPARATUS FOR FASTENING ARTICLES This application is a continuation of application Ser. No. 172.980. filed Aug. 19, 1972, now abandoned, which is a division of application Ser. No. 776,712, filed Nov. I8, 1968, now US. Pat. No. 3,616,034.

The present invention relates to a new and improved apparatus for adhesively fastening two members. More specifically, the present invention is directed to an apparatus for driving an adhesive material through a solid workpiece to oe spread at the interface thereof.

Accordingly, one object of the present invention is to provide a new and improved fastening device.

Another object is to provide a new and improved fastening device for providing the adhesive fastening of members.

A further object of the present invention is the provision ofa new and improved fastening device capable of driving an adhesive material through a solid workpiece.

Another object is to provide a liquid adhesive applying tool capable of driving a free body of adhesive through a solid workpiece and into an interface, which tool includes a liquid adhesive containing bore, a plunger movable in the bore, and a fluid powered impact member for applying an impact force to the plunger to discharge adhesive from an exit nozzle communicating with the bore.

Further objects and advantages of the present invention will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of the specification.

In accordance with these and other objects, there is provided an improved fastening device for driving adhesive through a solid workpiece, including an adhesive chamber communicating with a cylinder terminating in a nozzle. A plunger is provided in the cylinder for ejecting adhesive with great force and velocity. It has been found that the adhesive can be ejected with sufficient force to penetrate through a solid workpiece. The adhesive will spread at the interface of the members to provide the adhesive fastening of the members.

Many suitable drive devices may be provided for operating the plunger; however it has been found that a pneumatically operated piston and drive member engageable with the plunger function advantageously to provide the desired force and velocity for the adhesive.

The present invention is also directed to a new and improved method of fastening members together. Briefly the method consists of driving an adhesive through a solid workpiece by its own inertia, being ejected with sufiicient force and velocity to penetrate the solid workpiece. The adhesive is then spread at the interface of the members to provide an adhesive bond.

Advantageously it has been found that the adhesive will penetrate through a workpiece, to the interface between a workpiece and a base member, and will spread at the interface whether or not the materials of the workpiece and base member are similar or dissimilar. Thus the method and apparatus according to the present invention may be useful for many purposes such as securing furring strips to concrete or block bases; securing dry wallboard or paneling directly to concrete or block surfaces without the use of furring strips; securing paneling or other veneer to base structures, and many other uses.

For a better understanding of the present invention, reference may be had to the accompanying drawings wherein:

FIG. 1 is a fragmentary view of a fastening device according to the present invention;

FIG. 2 is a fragmentary view illustrating a method of use of the fastening device of FIG. 1;

FIG. 3 is a fragmentary view, similar to FIG. 2, illustrating another mode of use of the fastening device of FIG. 1;

FIG. 4 is a cross sectional view of a typical adhesive joint, taken along line 4-4 of FIG. 3;

FIG. 5 is a fragmentary view illustrating the adhesive fastening of a workpiece to a glass base member;

FIG. 6 is a fragmentary view illustrating the securing of furring strips to a concrete wall; and

FIG. 7 is a cross sectional view of the furring strips and wall structure of FIG. 6.

Referring now to the drawings, and particularly to the embodiment of FIG. 1 thereof, there is illustrated a fastening device 10 for ejecting adhesive with sufficient force and velocity to cause the adhesive to penetrate through a solid workpiece. More specifically the fastening device 10 includes a nose portion 12 having a chamber 14 for adhesive material. A nozzle 16 communicates with the chamber 14, and includes a cylinder 18 having one end 18a opening into the chamber 14, and having a restricted exit 18b of substantially reduced cross section at its other end. The nozzle structure 16 is shown as being threadedly or removably mounted on the nose portion 12 to permit nozzle 16 having different openings or exits 18b to be used. A plunger 20 is provided for reciprocal movement within the cylinder 18, and a spring 22 is provided for returning the plunger to its normal or at rest position as illustrated in FIG. 1. Projections 16a extending upwardly from the body of the nozzle 16 guide the plunger 20 into the cylinder 18, and further serve to provide passageways for the adhesive to fill the cylinder 18 after the plunger 20 has been returned to its normal position.

Although different types of adhesives with different compositions and characteristics can be used to carry out the present invention, an additional advantage is obtained using adhesives which have a rapid set or quickly attain green strength" to permit the joined parts to be self-supporting. As an example, epoxy adhesives and hot melt adhesives are satisfactory and are well known. Hot melt adhesives, for instance, become viscous when heated to a temperature which may, with different compositions, be in the range of 250 F. to 400 F. To this end, the chamber 14 is surrounded by a suitable electrical heating jacket 24 which may, if desired, be thermostatically controlled to provide the required temperature. The material forming the nose portion 12 preferably is a good thermal conductor and provides a heat source for maintaining the adhesive at the desired temperature or viscosity.

If desired, means may be provided for insuring that the cylinder 18 is maintained full of adhesive when the plunger 20 is withdrawn. To this end there is provided a fluid connection 26 for admitting pressurized fluid such as compressed air to the chamber 14 to maintain a slight pressure above atmospheric within the chamber 14.

The plunger 20 may be driven through its drive stroke in any suitable manner. In the illustrated embodiment a standard commercial pneumatic fastener driving tool has been adapted to drive the plunger 20. Such a tool can include a housing 30 having defined therein a cylinder 32 slidably receiving a drive piston 34. A drive member 36 is connected to the drive piston 34. The drive piston and associated drive member are operated through a drive stroke upon depression of a trigger 38 and are returned either automatically or upon release of the trigger 38. One such tool is shown and described in detail in US. Patv No. 3,685,396 issued Aug. 22, l972 to Allen R. Obergfell.

The drive member 36 is generally cylindrical and moves through a drive track 40 defined in the nose portion 12. Since the end 36a of the drive member 36 is normally spaced above the top end of the plunger 20, the drive piston 34 and drive member 36 develop considerable velocity and inertia on operation prior to striking the plunger 20. The invention can also be carried out with a direct coupling between the piston 34 and the plunger 20.

When the fastening device 10 is to be operated, the exit opening 18b is placed adjacent the parts to be joined, and the trigger 38 is operated to render the pneumatically operated drive effective to move the drive piston 34 and drive member 36 downwardly through a drive stroke. At the end portion of this stroke, the lower end of the drive member 36 strikes the upper end of the plunger 20, and the plunger 20 is driven downwardly through the cylinder 18 with great force and speed so as to eject adhesive from the exit 18b with considerable velocity and with substantial force.

In one particular device 10 constructed in accordance with the present invention, the cross section of the cylinder 18 is 65 times the cross sectional area of the exit 18b, and the plunger 20 has a )4 inch diameter with a i inch stroke. When employing a pneumatically driven piston 34 and driver 36 having a normal velocity in the range of 90 feet per second, it is believed that the plunger 20 is impelled thereby at a speed in the range of 50 to 75 feet per second to propel the adhesive from the exit 18b at a substantially increased velocity. This velocity is sufficient to penetrate a substantial thickness of a solid workpiece, such as a wooden furring strip or veneer siding. Moreover, using a commercially available hot melt, liquid adhesive heated to the range of 250 to 400 F., the adhesive green sets in normal materials in 3 to 5 seconds to provide sufficient strength to maintain the parts in assembled relation.

Referring now to FIG. 2, there is illustrated a mode of use of the fastening device 10. As therein illustrated the nose portion 12 of the fastening device is placed against a workpiece 44 held against the base member 46. Both the workpiece and base member, in the illustrated embodiment, are similar, being formed of wood. Firing of the fastening device 10 is effective to drive a charge of adhesive 48 through the workpiece 44 so as to spread along the interface between the workpiece 44 and the base member 46.

FIG. 3 illustrates another mode of use of a fastening device 10 wherein the nosepiece 12 of the fastening device 10 is in close proximity to, but positioned spaced above, the workpiece 44 held against the base member 46. in similar manner a charge of adhesive 48 penetrates through the workpiece 44 and spreads at the interface between the workpiece 44 and the base member 46.

It has been found by experimentation that the positioning of a tool in accordance with both the embodiments of FIGS. 2 and 3 provides a satisfacto y bond with a minimum visual opening in the workpiece 44 by the penetration of the adhesive 48. However in certain applications and with certain materials the spacing of the nosepiece 12 above the workpiece 44 may provide a better appearing and less noticeable opening through the workpiece 44.

FIG. 5 illustrates the fastening of a strip onto hard material such as glass. More specifically there is illustrated a furring strip 52 which is secured to a glass base member 54 by use of the present method. Adhesive is directed through the furring strip 52 at a plurality of spaced points 56 so that the adhesive spreads at the interface between the strip 52 and the base member 54 as illustrated at 58.

FIGS. 6 and 7 illustrate the connection of workpieces 62 such as furring strips to a base member 64 here illustrated as a concrete wall. Each of the furring strips 62 is adhesively fastened in a plurality of spaced apart points by the penetration of suitable adhesive 66 through the furring strips.

In accordance with the method of the present invention, it has been determined that it is possible to control or achieve the spreading of the adhesive at the interface between the elements to be joined together. Although the phenomenon is not fully understood, it appears as if the controlled dispersion of the adhesive at the desired point is related to the nature of the discharged stream of adhesive and the nature of the workpieces to be joined. The nature of the adhesive stream is dependent on or varies with, for instance, the viscosity of the adhesive, the area of the discharge orifice, and the velocity of the discharged adhesive. Certain of these factors are interdependent and further dependent on, for example, the pressure applied to the adhesive 48 in the chamber 18 during the driving stroke. For instance, the force applied to the adhesive in the chamber 18 and the size of the exit opening 18b tend to change the temperature of the adhesive, and the change in temperature varies the viscosity of the adhesive in the discharged column.

By properly correlating the factors referred to above, it has been determined that the controlled dispersion of the adhesive at a desired interface between elements to be joined can be achieved. As an example, with two wooden workpieces to be joined, it has been determined that using hot melt adhesive at a given temperature and viscosity with a given air pressure for driving the piston 34, the stream of adhesive discharged from the tool 10 passes completely through both of the wooden workpieces. By reducing the air pressure for driving the piston 34 or by reducing the viscosity of the liquid adhesive, the adhesive stream discharged from the tool 10 passes through only the first of the two wooden workpieces and is dispersed or spread at the interface between the two workpieces to join them together. A variation in the nozzle orifice size can also be used to effect this control by increasing orifice area to reduce the workpiece penetration.

With more than two workpieces or laminae disposed adjacent each other to form a number of spaced workpiece interfaces, the nature of the liquid adhesive column can be controlled as described above to select the one of the interfaces at which spreading of the adhesive occurs. This permits the workpieces to be secured with different adhesives or at different times or permits only selected ones of the workpieces to be joined. All of this is accomplished without requiring physical separation of the plural workpieces and in those instances in which the workpiece interface is not accessible.

It has also been determined that when the nature of the liquid adhesive column has been determined to the extent necessary to obtain dispersion of the adhesive at the desired point or interface, the degree of spreading at the interface can be controlled by varying the quantity of liquid adhesive discharged and the discharge pressure used without losing the spreading at the interface. Generally, reduced discharge pressure and increased viscosity of the adhesive result in reduced spreading at the interface.

As indicated above, the achievement of spreading at an interface and the extent of the spreading are also dependent on the nature of the workpieces to be joined. It has been determined, for instance, that there is a necessity to exert some control over the nature of the discharged liquid adhesive stream when two wooden workpieces or a wooden workpiece and a lamina of drywall are to be joined at an interface between these two workpieces. On the other hand, when the liquid stream of adhesive is to pass through a drywall lamina or a wooden workpiece to an interface formed by a second and rather dense workpiece such as glass (FIG. 5) or concrete (FIG. 7), the nature of the liquid adhesive column does not require the same degree of control. In this situation, the adhesive spreading readily occurs at the interface, and changes in the adhesive column effect primarily a control over the degree of spreading.

It is also believed that the arrangement of the workpieces has an effect on the dispersion or spreading of the adhesive at a workpiece interface. As an example, using wooden workpieces to be joined and a discharged adhesive column of a given nature, the adhesive can be made to increase its penetration of the workpiece, even to the extent of passing through the workpieces, by applying a compressive force to the workpieces so that the interface between the workpieces is formed by a very small air gap. On the other hand, with the same workpieces and adhesive column, the removal of the clamping pressure increases the air gap at the interface and causes substantial spreading of the adhesive into the interface with very little penetration of the second workpiece.

Although the present invention has been described by reference to only a single embodiment thereof, and various modes of operation and methods of use thereof have been described, it will be apparent that numerous other modifications and embodiments may be devised by those skilled in the art and it is intended by the appended claims to cover all modifications and embodiments which fall within the true spirit and scope of the present invention.

What is claimed is:

1. Apparatus for driving adhesive through a solid workpiece to the interface thereof with a base member, said apparatus comprising in combination:

a portable hand-held tool including a housing and a handle;

a nose portion supported on said housing in a fixed position relative to said housing and adapted to be placed adjacent the workpiece;

a pneumatic cylinder in said housing and a piston in said cylinder movable toward and away from said nose portion;

control means including a trigger disposed adjacent said handle for moving said piston in a drive stroke toward said nose portion;

said nose portion including a first chamber for containing a body of liquid adhesive;

heating means mounted on said nose portion for heating said adhesive to a temperature sufficient to maintain said adhesive in a viscous condition;

an elongated second chamber in said nose portion substantially smaller than said first chamber, said second chamber having an inlet communicating with the first chamber at one end to permit liquid adhesive to flow from the first chamber into the second chamber;

a plunger supported in said nose portion extending through the first chamber and mounted for reciprocating movement along a path between a first position substantially removed from the second chamber and a second position at least partly in said second chamber;

a nozzle including a restricted orifice leading from said second chamber to the exterior of said nose portion;

means for normally urging said plunger toward said piston and out of said second chamber; and

a drive member supported by said piston and normally spaced from said plunger;

said drive member striking said plunger during said drive stroke for driving said plunger into said adhesive cylinder to propel said viscous adhesive from said nozzle at high speed in order to drive said adhesive through the solid workpiece by its own inertia and into the interface between the workpiece and the base member.

2. The tool set forth in claim 1 in which the second chamber comprises an elongated cylinder,

said end portion of the plunger means includes a cylindrical portion slidable within the elongated cylinder of the second chamber,

and the first chamber is disposed above a first end of the second chamber intermediate the second chamber and the drive member. 

1. Apparatus for driving adhesive through a solid workpiece to the interface thereof with a base member, said apparatus comprising in combination: a portable hand-held tool including a housing and a handle; a nose portion supported on said housing in a fixed position relative to said housing and adapted to be placed adjacent the workpiece; a pneumatic cylinder in said housing and a piston in said cylinder movable toward and away from said nose portion; control means including a trigger disposed adjacent said handle for moving said piston in a drive stroke toward said nose portion; said nose portion including a first chamber for containing a body of liquid adhesive; heating means mounted on said nose portion for heating said adhesive to a temperature sufficient to maintain said adhesive in a viscous condition; an elongated second chamber in said nose portion substantially smaller than said first chamber, said second chamber having an inlet communicating with the first chamber at one end to permit liquid adhesive to flow from the first chamber into the second chamber; a plunger supported in said nose portion extending through the first chamber and mounted for reciprocating movement along a path between a first position substantially removed from the second chamber and a second position at least partly in said second chamber; a nozzle including a restricted orifice leading from said second chamber to the exterior of said nose portion; means for normally urging said plunger toward said piston and out of said second chamber; and a drive member supported by said piston and normally spaced from said plunger; said drive member striking said plunger during said drive stroke for driving said plunger into said adhesive cylinder to propel said viscous adhesive from said nozzle at high speed in order to drive said adhesive through the solid workpiece by its own inertia and into the interface between the workpiecE and the base member.
 1. Apparatus for driving adhesive through a solid workpiece to the interface thereof with a base member, said apparatus comprising in combination: a portable hand-held tool including a housing and a handle; a nose portion supported on said housing in a fixed position relative to said housing and adapted to be placed adjacent the workpiece; a pneumatic cylinder in said housing and a piston in said cylinder movable toward and away from said nose portion; control means including a trigger disposed adjacent said handle for moving said piston in a drive stroke toward said nose portion; said nose portion including a first chamber for containing a body of liquid adhesive; heating means mounted on said nose portion for heating said adhesive to a temperature sufficient to maintain said adhesive in a viscous condition; an elongated second chamber in said nose portion substantially smaller than said first chamber, said second chamber having an inlet communicating with the first chamber at one end to permit liquid adhesive to flow from the first chamber into the second chamber; a plunger supported in said nose portion extending through the first chamber and mounted for reciprocating movement along a path between a first position substantially removed from the second chamber and a second position at least partly in said second chamber; a nozzle including a restricted orifice leading from said second chamber to the exterior of said nose portion; means for normally urging said plunger toward said piston and out of said second chamber; and a drive member supported by said piston and normally spaced from said plunger; said drive member striking said plunger during said drive stroke for driving said plunger into said adhesive cylinder to propel said viscous adhesive from said nozzle at high speed in order to drive said adhesive through the solid workpiece by its own inertia and into the interface between the workpiecE and the base member. 